In U.S. Pat. No. 3,992,952 assigned to the same assignee as the present application, there is described a control system for an angular displacement sensor. The ellipticity control system in the above-mentioned patent requires active feedback of the position of a point on the vibrating member. In the present invention, the need for active feedback is eliminated because the required control forces proportional to position are provided by a multiple electrode configuration.
The principal disadvantage of the ellipticity control system described in the above-mentioned patent is that there may be errors in synthesizing forces proportional to position of the vibrating member for purpose of ellipticity control. Since there is no need in the present invention to synthesize forces proportional to position of the vibrating member, this source of error is eliminated.